The present invention refers to an apparatus for measuring electromagnetic values of a coil, in particular for measuring the position of armature of a coil/armature magnetic system.
It is known to use various switches and sensors for measuring the position of the armature of a coil/armature magnetic system or the electromagnetic values of a coil. For example, inductive or capacitive proximity switches have been used to determine a certain position of the armature. Further, position sensors e.g. Hall probes or similar components have been described. For determining electromagnetic values of a coil, there are known various measuring circuits. However, apart from the fact that the measurements are partly dependent on the supply voltage and the surrounding temperature and thus inaccurate, the known proposals usually allow determination of only one or two positions of the armature, generally the end positions of the same. The switches or sensors used for the measurement are either directly attached to the armature the position of which is to be determined or at least have to be arranged in immediate vicinity of the latter. By virtue of these drawbacks, a miniaturization of measuring devices is not possible nor is it feasible to provide the measuring device at a spatial distance from the armature or coil.